A conventional tape cassette has a casing of plastic material which is made in two halves which are secured together by means of screws screwed into stationary posts provided near the corners of the cassette. In order to provide sufficient strength it is necessary for the walls of the plastic casing to be relatively thick so that it is difficult to make the cassette smaller than a standard size cassette.
As a means for eliminating the above noted difficulty and insufficiency, it has been proposed to form the cassette halves as thin metal plates which are secured together with normal screws and stationary posts. However, with this construction it is still necessary to provide screws and stationary posts for fixing the two halves of the cassette together. Moreover, the construction does not make possible small miniaturization.